Use the “passwords” feature to check if one of yours is compromised. If it shows up, never ever reuse those credentials. They’ll be baked into thousands of botnets etc. and be forevermore part of automated break-in attempts until one randomly succeeds.
These kinds of breaches are at the site level. Not much you can do as a regular user if the company doesn’t hash or salt their passwords, for example.
Not from what the article says